Improved solenoid having pin and socket connections to the solenoid winding

ABSTRACT

A solenoid including a housing having a cap which constitutes a closure at one end of the housing, a winding within the housing, and a terminal member on the exterior of the cap, the terminal member being electrically connected to the winding. The terminal member is electrically connected to the winding by way of a conductive pin which is carried by the cap and which extends within the housing, and a conductive socket which is connected to one end of the winding. The pin engages in the conductive socket when the solenoid is assembled, and thereby electrically interconnects the terminal member and one end of the winding.

United States Patent Inventor Frank Phillip Dew Birmingham, England Appl. No. 826,643 Filed May 21, 1969 Patented Mar. 23, 1971 Assignee Joseph Lucas (Industries) Limited Birmingham, England Priority May 27, 1968 Great Britain 25192 IMPROVED SOLENOID HAVING PIN AND SOCKET CONNECTIONS TO THE SOLENOID WINDING 1 Claim, 7 Drawing Figs.

[56] References Cited UNITED STATES PATENTS 2,472,553 6/ 1949 Theunissen 335/256X 2,975,340 3/1961 Jencks et a1. 335/257X 2,987,655 6/1961 McCurdy 335/256 3,134,932 5/1964 Ray 335/257 Primary Examiner-43. Harris Attorney Holman, Glascock, Downing & Seebold ABSTRACT: A solenoid including a housing having a cap which constitutes a closure at one end of the housing, a winding within the housing, and a terminal member on the exterior of the cap, the terminal member being electrically connected to the winding. The terminal member is electrically connected US. Cl 335/256, to the winding by way of a conductive pin which is carried by 336/192, 339/176 the cap and which extends within the housing, and a conduc- Int. Cl H011 7/08 tive socket which is connected to one end of the winding. The Field of Search 339/14, pin engages in the conductive socket when the solenoid is as- 143, 176 (M), 191 (M), 195 (M); 336/192; sembled, and thereby electrically interconnects the terminal 335/255, 257, 256, 260, 278 member and one end ofthe winding.

PATENTEDHARZSIS?! 3.571.770

SHEET 2 o 6 Mi v 1 a INVENTOE AT'i'EkN EYS PATENTED mes I97! SHEET 3 0F 6 iNV NT R B MMM J ATTOENEYS IN NT 5Y0 I J E E EYS MM 1 W PATENTE'D m2 3 an sums UF 6 scp INV mg I AWPNEYS nuns-roves SQELENQW Elm/L NG PEN AND d'il fillldll 'I'G SQLENQED WmlDllNt'l This invention relates to solenoids of the kind comprising a housing including a cap which constitutes a closure at one end of the housing, a winding within the housing, and a terminal member on the exterior or the cap, the terminal member being electrically connected to said winding.

According to the invention, in a solenoid of the kind specified, said terminal member is electrically connected to a conductive pin which is carried by the cap and which extends with the housing, one end of said winking is electrically connected to a conductive socket member within the housing, and said pin is engaged with said socket member and thereby electrically interconnects said terminal member and said one end ot the winding.

One example of the invention is illustrated in the accom panying drawings wherein,

Flt ll a sectional view of a solenoid,

EEG. 2 is a fragmentary sectional view of the solenoid shown in Flt}. l, I

FllG. 3 is a fragmentary exploded perspective view of the solenoid shown in MG. 1,

lFlG. d is an enlarged, perspective view of part of FIG. 3 partly assembled,

FIG. 5 is a sectional view of part of a modification of the solenoid shown in FIG. ll,

MG. 6 is an exploded perspective view of part of the modified solenoid, and

FIG. '7 is a view similar to H6. 6 of an alternative construction.

Referring first to FIGS. 1 to 4 of the drawings, the solenoid includes a conductive cylindrical casing 111 which is partially closed at one end by an inwardly directed peripheral flange l2. At its end remote from the flange 112, the casing ll is formed with an internal shoulder l3 against which abuts an annular conductive plate lid. The plate 14 is trapped in position against the shoulder 13 by spinning over the end of the casing ii. Extending axially within the casing, and projecting from the central hole of the flange 12 is a brass sleeve 15 within which is slidably mounted the plunger (not shown) of the solenoid. Secured to the plate 14 and closing the central hole therein is a metal pole piece 36. The pole piece 16 extends axially within the sleeve l5, and the plunger of the solenoid is attracted towards the pole piece it? use. Surrounding the sleeve 35 is a moulded synthetic resin former 17 which includes a pair of outwardly directed peripheral flanges l8, 19 at opposite axial ends thereof. The flange lb of the former l7 abuts against the flange l2 of the casing, and a spring steel washer 21 interposed between the flange 19 of the former l7 and the plate 1 The spring steel washer 21 includes a plurality of resilient arms 22 which engage the plate l4, and the washer 21 takes up any free play between the plate 14 and the flange if; so that the former i7 is held firmly in position. Secured to the end of the casing ll remote from the flange 112, by screws (not shown) is a moulded insulating end cap 23. The end cap 23 is hollow and supports a pair of externally screwthreaded heavy duty copper terminals ll, 42 which include. respective integral contact pieces 53, within the hollow of the end cap A copper bridging piece 45 is carried at one end of a push rod 26 which is slidably mounted within the pole piece E6, the arrangement being such that when the plunger of the solenoid is drawn towards the pole piece lid, it engages the push rod and moves the push rod 2 3 so that the bridging piece completes the circuit between the heavy duty terminals dli, in use, the terminals d1, 42 are connected between the battery and the starter motor of a road vehicle, so that energization oi the solenoid completes the circuit to the starter motor.

The former 17 carries a pull-in winding 2, and a hold-on winding The flange il of the former i7 is provided with a pair of diametrically opposite J-shaped slots (one of which is shown at 2?), and adjacent each slot 27 the flange l9 includes an integral, axially extending housing 26. The housings 2% extend through corresponding holes in the plate lid and the washer 2i and located within each of the housings 28 is a conductive terminal member 29. Each of the terminal members 29 includes a socket 3i and a channel portion 32. One end of the winding 26 is soldered to the washer 211, and so is electrically connected to the casing 111 of the solenoid. One end of the winding 25: is led through one of the slots 27 and into the respective housing 2b. Within the housing 28 said one end of the winding 25 is engaged within the channel portion 32 of the respective terminal member 29, and is soldered to the portion 32 to electrically connect said one end of the winding 25 to the respective terminal member 29. The other ends of both of the windings 25, 2d are led through the opposite slot 27, and are similarly electrically connected to the other terminal member 29. The wire constituting the windings 25, 26 is coated with a selfluring varnish which insulates adjacent convolutions of the windings from one another, and since the varnish is self-tluiring there is no need to remove the varnish from the ends of the windings prior to soldering the ends of the windings to their respective terminal members.

A blade terminal 33, and a conductive connecting strip 36 are secured to the outer surface of the cap 23, at diametrically opposite points, by respective conductive rivets 34. Each of the rivets 34 extends through the cap 23, and at its ends remote from the exterior of the cap 23 defines a conductive pin 35. When the cap 23 is secured to the casing 111, the pins 35 enter the sockets 31 of the terminals 29 respectively, the pin 35 associated with the terminal 33 entering the socket 31 which is electrically connected to said other ends of both the windings 25, 26, so that the blade terminal 33 is electrically connected to both windings 25, 26, and the pin 35 associated with the connecting strip 36 entering the socket 31 which is electrically connected to said one end of the winding 25, so that the connecting strip 36 is electrically connected to the heavy duty terminal d2, which in use, is electrically connected to the starter motor.

In order to assemble the solenoid the windings 25, 26 are wound onto the former 17, said one end of the winding 25 is soldered to the respective terminal 29 which is in position in its respective housing 28 and said other ends of both of the windings are soldered to the other terminal member 29 which is also in position in its respective housing 28. The former l7 is then inserted into the casing Ill, and the spring washer Zl is located on top of the former 17, in contact with the flange 19 of the former l7. Said one end of the winding 26 is then threaded through a hole in a tag on the plate 21 and is so]- dered to the tag. The plate lid is then placed on top of the washer 2i and is urged axially towards the flange 12 of the casing to stress the washer 2i, and the wall of the casing ll is then spun over to trap the plate 14 and the former ii? in position. The end cap 23 is then engaged with the casing ll, so that the pins 35 enter the sockets Fill and the end cap is then secured to the casing ll by screws (not shown) which extend through the end cap 23 into engagement with the plate M.

in use the blade terminal is electrically connected to the battery of the vehicle through the starter switch of the vehicle, the case 111 of the solenoid is earthcd through its mounting bracket, the heavy duty terminal 42 which is electrically connected to the winding 25 is connected to earth through the field coil of the starter motor, and the heavy duty terminal at is connected to the battery. Thus, when the starter switch of the vehicle is closed both the winding 25 and the winding as are energized and the plunger of the solenoid is drawn towards the pole 16 thereby moving the bridging contact 45 into engagement with the contacts 43, 443 and completing the circuit to the starter motor of the engine. Since the winding 25 is electrically connected at one end to the heavy duty terminal 32 which is connected to the field winding of the starter motor, then when the bridging contact 485 completes the circuit between the heavy duty terminals 431,42, then the winding 2:3 is short-circuited and only the hold-on winding 26 remains energized. The winding remains energized to hold the plunger of the solenoid in a position where the contacts 43, 4 are bridged, until the starter switch of the vehicle is opened.

The push rod 241 is urgedbyaspn'ng 24a in a direction todisengage the bridging contact 45 from the contacts 43, &4 and thus when the starter switch of the vehicle is opened the plunger of the solenoid is no longer attractedtowards the pole l6, and the push rod 24 is moved by the spring 24a in a direction to break the circuit between the contacts 43, 44.

In the modification shown in FIGS. and 6, the blade terminal 33, the connecting strip 36 and the rivets 34 are dispensed with. The blade terminal 33 and its associated rivets 34 are replaced by a terminal post 4l6 which extends through the cap 23 and defines the conductive pin 35 at its inner end. The connecting strip 36 is replaced by a rigid conductive lead 57 which is enclosed within a bore in the cap 23, the cap 23 being moulded around the lead 37. The lead 47 defines the other conductive pin 35 at one end, and the connection between said conductive lead and said one end of the winding 25, and the connection between the post 46 and said other end of the windings 25, 26 being made through pins 35 and terminais 29 as described above. The terminals 41, 12 of the construction described above are replaced by steel slugs (one of which is shown at dd). The steel slugs 48 are secured in the cap 23, during manufacture of the cap 23, by moulding the cap around the slugs. At its inner end, each of the slugs 48 has a copper contact piece 48a welded thereto, the contact pieces 4&1 being engageable by the bridging piece 45 of the solenoid. At its end remote from the contact piece 43a each slug 48 is formed with a screwthreaded bore 49 and the slugs 4b are electrically connected to the battery of the vehicle, and the starter motor of the vehicle respectively, through connectors 51, 52 which are secured to the outer ends of the slugs 48 by conductive screws 53. The screws 53 engage in the bores 49 of the slugs 4 3, and the ends of the connectors 51, 52, and the projecting portions of the slugs 48 are enclosed in protective rubber gaiters 54, 55. The conductive lead 47 extendswithin its respective bore in the cap 23 into engagement with the slug which is electrically connected, in use, through the connector 52 to the starter motor. As shown in FIG. 6, the cap 23 carrice a further conductive post 56. The conductive post 56 extends through the cap 23, and is electrically connected to one end of a connecting strip which is housed within the casing of the solenoid, the other end of the connecting strip being connected to earth through one of the heavy duty terminals and the starter motor. A ballast resistor mounted externally is electrically connected to the projecting portion of the post ss. The operation of the modified solenoid is identical with that described above.

In the alternative shown in H6. 7, the steel slugs it: are extended to define terminal posts. The connections to the steel slugs 48 are made by way of conductive socket connectors 57 which are secured to their respective slugs 33 by screws 53. The socket connectors 57 are provided with protective, rubber gaiters 5 5.

lclaim:

1. A solenoid including a housing comprising a casing closed by a cap, first and second windings within the casing, first, second, and third terminal members on the exterior of the cap, first and second conductive socket members within the housing, the first socket member being electrically connected to one end of the first and second windings and the other end of the first winding being electrically connected to the second socket member, first and second conductive pins carried by the cap and extending within the housing into engagement with the first and second socket members respectively, the first and second pins being electrically connected to the first and second terminal members respectively, a plungerslidably mounted within the housing and movable in response to energization of the solenoid, first and second contacts within the housing electrically connected to the second and third terminal members respectively, and a bridging piece engageable with said first and second contacts by movement of said plunger, so as to electrically interconnect the second and third terminal members, the other end of said second winding being earthed in use. 

1. A solenoid including a housing comprising a casing closed by a cap, first and second windings within the casing, first, second, and third terminal members on the exterior of the cap, first and second conductive socket members within the housing, the first socket member being electrically connected to one end of the first and second windings and the other end of the first winding being electrically connected to the second socket member, first and second conductive pins carried by the cap and extending within the housing into engagement with the first and second socket members respectively, the first and second pins being electrically connected to the first and second terminal members respectively, a plunger slidably mounted within the housing and movable in response to energization of the solenoid, first and second contacts within the housing electrically connected to the second and third terminal members respectively, and a bridging piece engageable with said first and second contacts by movement of said plunger, so as to electrically interconnect the second and third terminal members, the other end of said second winding being earthed in use. 